Benedict Cumberbatch stalks into a room full of nervous reporters, wearing a plaid shirt under a padded leather jacket, his crowning glory shorn of trademark Sherlock curls and restyled into a close-cropped block with its edges teased by wax into tiny, furry undulations.
He brings to the interview a styrofoam cup of hot coffee murmuring a faint, fresh mist on the black-rimmed glasses perched on his face. The glasses come off immediately as the actor takes a seat, facing his questioners head-on with a clear-eyed stare.
Cumberbatch is here to answer questions about his latest movie pursuit as cryptographer Alan Turing in director Morten Tyldum's The Imitation Game. Except, of course - that he has already pre-empted them all with a stream of ready, authoritative oration.
"He was wonderful, he was entertaining... I spoke to his niece after I read the script and was researching the project. She said he never made us feel we were talked down to. He used to crack jokes, he used to be able to play chess with his back turned to the board," the 38-year-old actor recalls.
"He's an extraordinary human being, not such an easily boxed, outsider autistic genius. Yes, the film is about celebrating people who are different - but we define people as different at our own cost. What delineates different behaviour or marks somebody as being remarkable can also be examined under a light that also relates them to who we all are as human beings."
So this is the actor who dashed a few million female hopes two months ago when his parents - both also professional actors - broke news of his engagement to theatre director Sophie Hunter in the pages of London's The Times newspaper.
Coming across almost as arrogant and intelligent as his best-known TV persona of Sherlock Holmes, Cumberbatch charms through unrelenting, beautifully articulated talk.
At the same time, there is a twinkle in his eye which recalls the playful side of a personality that the Internet has turned into memes: through endless re-tweets of a famous photo-bomb at last year's Academy Awards; clips showing his self-conscious mirth at his inability to pronounce "penguin" on a TV chat show.
And still the actor continues: "His character was formed from his circumstances. I don't think he was born with Asperger's. He was born into foster care, his family was away in India on a diplomatic career, he came back when he was four, he had a stammer.
"He went to school where he was to make friends - you can't do that very easily if you had a stammer. All these things fell in... there are no visual or audio recordings of him, most of it is hearsay. At the end, I just sometimes went from the outside in, sometimes from the inside out - I put together the character just bit by bit really - it's different every day."
In The Imitation Game, Cumberbatch plays Turing, maligned mathematician and father of the modern computer. At the height of his career, Turing led a team of code analysts at Bletchley Park in England that broke the German Enigma encryption machine, bringing World War II to an earlier end.
In 1952, however, Turing was picked up by the police for "homosexual acts" and subjected to chemical castration, before he tragically killed himself two years later at the age of 41. It was not until 2009 that the British government issued a public apology for "the appalling way in which he was treated".
"This is the same person who in the dark night of his soul took a carving knife in his kitchen and tried to gouge (the chemical packet) out of his leg," Cumberbatch says, his voice raised.
"A leg that had carried him through life as a genius, as a homosexual and a marathon man.
"This man's a national hero, he should be with Newton and Darwin, he's a war hero, a gay icon. For that alone, he should be on the front cover of textbooks, both history and scientific ones, and god knows, even banknotes."
Visibly angry, the actor goes into full throttle as he gets to the heart of his speech, persuading you that he agreed to take on the role if only to tell the story of a massive injustice that continues to be wrought upon communities around the world today.
"When I read the script, I was amused and intrigued and flabbergasted and then confused and angry and very upset," he says.
"When I was doing the last scenes, there were a couple of takes in the beginning of the day where I couldn't stop crying. It wasn't good acting, I was just being in tune with the fact that this really happened.
"It was near the end of me playing him, so I felt defensive of him. It destroyed me and then I couldn't bear to carry on. It still upsets me.
"People have been beheaded in parts of the world because they are gay. It is barbaric to think it's still going on here, the birthplace of Western democracy. But you know - the birthplace of democracy, Greece - has seen the rise of the Golden Dawn, and men and women being beaten up in public because of being gay. Russia's attitudes towards homosexuality - it's kind of terrifying.
"This isn't a history lesson. This is a reminder to us that people scapegoat minorities in times of hardship or in times of nationalism or fascism. We have to be on our guard for it, it seems to be a human condition."
You instinctively think to applaud, but the actor glides into the next topic of conversation with public schoolboy charm intact and nary a missed beat. He reminds us that there is also a lot of humour in the film - if only for the joy and silliness found within Turing himself.
"It's part of the script's charm, it's part of Alan's charm," Cumberbatch says. "He's rightfully funny, he's not unintentionally funny. It's not always about him being funny, we have to show him for who he was, not wink at the audience just to make them laugh. It was sometimes about him being witty."
Set in the 1940s, the movie shows Cumberbatch at first interacting awkwardly with a team of fellow mathematics geniuses staffed by Allen Leech (TV's Downton Abbey), Matthew Goode (A Single Man, 2009) and - the only female presence who also provides vague comic relief - Keira Knightley.
While the actor attended the ultra-posh Harrow School, eventually graduating into a theatre course at the University of Manchester and, later, the London Academy Of Music & Dramatic Art, he admits that he is not a numbers man.
"I tried my hardest, because it's important to try because it was such an important part of the story," he says. "But I'm not a pure maths PhD. I got a B in GCSE maths, which is not quite a disgrace but - frankly... probably it is."
Everyone laughs awkwardly, but he has a larger point to make. Mindful of the impression that he has been lauded mainly for his interpretations of brainiacs on the autistic spectrum, he is adamant to show that there are more strings to his bow.
"I've played intelligent people, I've played stupid people, I've played corrupt people, I've played heroes, I've played mixtures of all those things. The extraordinary ones stand out - if you look closely at IMDB, you'll see what I've done, but I always get defensive about this," he explains.
"Look at the flamboyance of Sherlock compared with this quiet, focused mind. It's not all about proving other people wrong. With Sherlock, it's a game. This guy is a bit quiet."
Next year, Cumberbatch will appear as Richard III in a marathon series of BBC adaptations of four Shakespeare plays. Meanwhile, tickets to his earlier, autumn run this year as Hamlet at the Barbican are already sold out. Fans had snapped up the London theatre's allocation for the show within seven hours.
What, really, is the deal over Cumberbatch?
In 2007, the English actor was still playing a bug-eyed villain - no less than a rapist - in Atonement opposite Knightley. In 2013, he was Julian Assange in The Fifth Estate, preacher-planter William Prince Ford in 12 Years A Slave and the voice of the dragon Smaug in The Hobbit: The Desolation Of Smaug (2013) and The Hobbit: The Battle Of The Five Armies (2014).
Statistics point to a career turnaround via the bright-boy role of Sherlock in 2010, but Cumberbatch's old friend Knightley thinks it was simply down to having it all from the start.
"He's always worked the most of any actor I've known. Everybody in the industry always thought it was a matter of when... it wasn't a surprise when it happened," the actress tells reporters in a separate interview on the same day. "Benedict's always had a lot of self-belief and he knew that in the best way. And his work has always been really very solid."
His fans will have you know that he was already highly decorated on the floorboards through prestige outings in London's West End and multiple awards following head-turning stints alongside star directors such as Tom Stoppard and Nicholas Hytner.
And then, there is the wishful Renaissance-man aura that the actor projects: via TV character Sherlock's polyglottism, via his own witticisms on and off stage, via apocryphal tales of his famous rugby tackles at school, via his early adventures in oil painting and his stint as an English teacher at a Tibetan monastery in India while trying to "find himself" at the age of 18.
The interview runs to an end just as you think the actor is about to begin a thoughtful telling of another important story circling an important political issue.
But the master controller of the game himself smiles quietly upon receiving a cue from a PR assistant, gliding out of his seat with another twinkle in his eye as he rocks on to the next interview.
Recorders come to a halt. Chairs are pushed back in a mini frenzy.
The coffee is cold. The actor appraises its value for the next round of questions in another plush room at London's Claridge's hotel. He makes an offhand decision.
"Well," he says, brisk with business. "You can have that."
The Imitation Game opens in Singapore tomorrow.